JP2833741B2 - Lithographic printing plate manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a lithographic printing plate according to a silver salt diffusion transfer method.

[0002]

BACKGROUND OF THE INVENTION The principle of the silver complex diffusion transfer reversal method referred to as the DTR method is described in, for example, US Pat.
e "Photographic Silver
Halide Diffusion Process
s "-The Focal Press-London
and New York, (1972).

[0003] In the DTR-method, the undeveloped silver halide of the photographic silver halide emulsion layer material which has been exposed in information is converted into a soluble silver complex compound using a so-called silver halide solvent, which is converted to an image-receiving element. Where it is reduced with a developing agent, usually in the presence of physical development nuclei, to form a silver image having an image density value that is inverted with respect to the black silver image obtained in the exposed areas of the photographic material ("" D
TR-image ").

[0004] The DTR-image containing material can be used as a lithographic printing plate, in which case the DTR-silver image area is water-based.
A water-repellent ink-receptive area is formed on a receptive ink-repellent background. For example, a typical lithographic printing plate is, for example, EP
-A-423399 and EP-A-410500.

DTR-images are also known as photographic silver halide emulsion materials, which are another element in the image-receiving layer of a sheet or web material (so-called 2-sheet DTR elements), or mono-sheet elements, comprising at least one layer. A photographic silver halide emulsion layer can be formed in the image-receiving layer of a so-called single support element, which integrally comprises the image-receiving layer in a water-permeable relationship therewith. The latter mono-sheet type is preferred for the production of offset printing plates by the DTR method.

[0006] As with other printing plates, the printing plates obtained according to the DTR-method have high printing durability, good ink receptivity in the printing area, and lack of ink receptivity in the non-printing areas (contamination). No) is necessary. The limited number of copies that have to be discarded due to poor ink acceptance in the printing area and / or ink acceptance in the non-printing area during the start of the printing process, especially in small printing operations More desirable in the case. In addition to the above requirements, the printing plate preferably exhibits a high resolution.

[0007] In order to obtain these required excellent printability using a printing plate obtained according to the DTR-process, several treatments of the developed mono-sheet DTR-material have been proposed. In EP-A 590,204 it was proposed to treat the developed monosheet DTR-material with a neutralizing solution having a pH lower than 7 and containing a meso-ionic compound. A reduction in the number of copies that must be discarded and an increase in resolution have been found. However, meso-ionic compounds are expensive and the results achieved are still unsatisfactory.

[0008] Neutralizing solutions having a pH of about 5.6 and possibly containing cysteine have also been used to achieve the purpose of reducing the number of waste copies during initiation. EP-A 9
4200189.2 treats the developed monosheet DTR-material with a neutralizing solution having a pH of 5 to 7 and containing a total concentration of phosphate ions of 0.2 mol / l to 0.4 mol / l. It is disclosed to do. EP-A 95200555.
1 is the developed mono-sheet DTR-material from 5 to 10.5
And treating with a neutralizing solution containing specific amines.

Although all such neutralizing solutions are somewhat effective in reducing the number of waste copies during initiation, they are inherently low in processing capacity and must be refreshed frequently. In fact, if the neutralizing solution is used for a long time to process a certain amount of developed imaging element, the resulting printing plate will provide a large amount of wasted copies for contamination during start-up. For economic and ecological reasons, and for convenience, it is desirable to increase the volume of these neutralization solutions.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to have excellent printability.
That is, it has excellent ink receptivity in the printing area,
An economical, ecological and simple method for the production of lithographic printing plates according to the DTR-method, without ink receptivity in the non-printing area and with a limited number of waste copies during start-up It is to provide.

Further objects of the present invention will become clear from the description hereinafter.

According to the present invention: an image-forming element comprising, on a support, a photosensitive layer containing a silver halide emulsion and an image-receiving layer containing physical development nuclei, is image-wise exposed; And developing with an alkaline processing solution in the presence of a silver halide solvent;
Has a pH of 0.5, has a hydrophobizing agent and antioxidant activity
A method for producing a lithographic printing plate according to a silver salt diffusion transfer method, comprising a step of neutralizing with a neutralizing solution containing a drug and a buffer, wherein the neutralizing solution contains a salt of sulfurous acid. You.

[0013]

DETAILED DESCRIPTION OF THE INVENTION
Has a pH of ~ 10.5, hydrophobizing agent, buffer , antioxidant
With a lithographic printing plate that is neutralized with a neutralizing solution containing an active agent and a salt of sulfite, the number of copies that must be discarded during the start of the printing process increases the number of developed image It was found that even when the forming elements were treated with the neutralizing solution, a limited number remained. However, the processing capacity of the neutralizing solution is very limited if it does not contain sulfurous acid salts.

Preferably, the salt of the sulfite is sodium or potassium sulfite or bisulfite. The amount of the salt is 1g
/ L to 200 g / l, preferably 2 g / l to 15
g / l is more preferred.

The neutralizing solution comprises a buffer, preferably a phosphate or citrate buffer, more preferably monosodium and / or monopotassium dihydrogen phosphate, most preferably from 20 g / l to 80 g / l. Include in quantity. The combination of monosodium and monopotassium dihydrogen phosphate can be used in solid form and / or in a concentrated form of the neutralizing composition which after dilution with water gives the neutralizing solution of the invention.

The pH of the new neutralized solution at 25 ° C. is preferably 5 to 9, more preferably 5.5 to 8,
It can rise to a value of about 10.5 during use.
The pH of the new neutralization solution can be adjusted, if necessary, by adding an organic or preferably inorganic acid or inorganic alkali or vice versa to the aqueous solution according to the invention.

According to the present invention, the neutralizing solution may also contain a hydrophobizing agent for improving the hydrophobicity of the silver image obtained in the image receiving layer. The hydrophobizing agents used in connection with the present invention are compounds which can react with silver or silver ions and are hydrophobic, ie insoluble or only slightly soluble in water. Generally, these compounds contain a mercapto group or a thiolate group, and one or more hydrophobic substituents, for example, an alkyl group having at least 3 carbon atoms. Preferred hydrophobizing agents are DE-A 1,228,927.
-1,3,4-thiadiazoles, 2-mercapto-5-alkyl-oxa-3,4-diazoles, and US-P 4,563,410.
-Mercapto-1,2,4-triazoles and aryl-substituted mercaptotetrazoles.

Particularly preferred hydrophobizing agents in connection with the present invention are aliphatic chain-substituted mercaptotetrazoles having at least 5 carbon atoms, more particularly the following formula (I):

[0019]

Embedded image

Wherein Z represents alkylaryl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl and most preferably substituted or unsubstituted alkyl.

Specific examples of hydrophobizing agents according to formula (I) are given in Table 1.
Listed in

[0022] According to the present invention, the hydrophobizing agent is present in the neutralized solution at least 0.1 g / l, more preferably at least 0.2 g / l.
l, and most preferably at least 0.3 g / l. The maximum amount of hydrophobizing agent will be determined by the type of hydrophobizing agent and the like. Typically, the concentration of the hydrophobizing agent is 1.
It is preferably at most 5 g / l, more preferably at most 1 g / l.

The neutralizing solution of the present invention is preferably a blocking compound,
More preferably, the phosphonic acid, (1-hydroxyethylidene) bis- (Henkel, Belgium)
In the name of RPINAL SL and Monsanto,
Belgium sold as DEQUEST 2010) or its disodium salt (Hankel, B.
e.g., sold under the name TURPINAL 2NZ). The amount of the blocking agent is 0.100 to 10 g / l.
Is preferably included.

The neutralizing solution contains an agent having an antioxidant activity, for example, sodium benzoate, in addition to the sulfite salt. The amount of the drug having antioxidant activity is 0.100 to 1
It is preferably contained at 0 g / l.

The neutralizing solution preferably contains an amine. The amine preferably corresponds to the formula: NR ¹ R ² R ³ ,
In the formula, R ¹ represents a C ₁ -C ₁₂ hydrocarbon group containing a hydrophilic group, and R ² and R ³ each independently represent hydrogen, a C ₁ -C ₁₂ hydrocarbon group, or R ² and R ³ is completed together with the atoms to which they are attached a 5- or 6-membered ring, provided that at least one of the groups represented by R ² and R ³ are hydrogen or an aliphatic group.

The C ₁ -C ₁₂ hydrocarbon group may be unsubstituted or substituted C ₁ -C ₁₂ , each of which may contain one or more divalent linking groups, such as —O—, —S— and the like. Alkyl group, unsubstituted or substituted C ₁ -C ₁₂ alkenyl group, unsubstituted or substituted C ₁ -C ₁₂ alkynyl group, unsubstituted or substituted C ₅ -C ₁₂ cycloalkyl group, unsubstituted or substituted C ₇ -C ₁₂ aralkyl groups, including unsubstituted or substituted C ₆ -C ₁₂ aryl, and unsubstituted or substituted C ₄ -C ₁₂ heterocyclic group, the C ₁ -C ₁₂ hydrocarbon group, at least 1 if showing the R ¹ Substituted by two hydrophilic groups.

The hydrophilic group includes an amine group, an ammonium group,
It can be a hydroxyl, a sulfo group or a carboxyl.

The compounds can be prepared by well-known methods, for example by reaction of ammonia or amines with suitable hydrocarbon halides, sulfonates, oxides and the like.

More preferably, R ¹ represents a C ₁ -C ₁₂ alkyl group substituted by a hydrophilic group, and R ² and R ³ each independently represent hydrogen or an unsubstituted or substituted C ₁ -C ₁₂ alkyl group. Show. Still more preferably, R ¹ represents a C ₁ -C ₈ alkyl group substituted by a hydrophilic group, and R ² and R ³ each independently represent hydrogen, an unsubstituted C ₁ -C ₅ alkyl group, or a hydrophilic group. Represents a C ₁ -C ₅ alkyl group substituted by

The ratio of the number of hydrophilic groups to the number of carbon atoms excluding carboxyl carbon atoms in the compound is preferably at least 0.1, more preferably at least 0.1.
2, most preferably at least 0.3.

Preferably, at least one of the hydrophilic groups is hydroxyl. More preferably, the hydroxyl will be at least 20% by number of hydrophilic groups,
Even more preferably it is at least 40% by number and most preferably it is at least 50% by number.

Highly preferred compounds are alkanolamines, which can be of the third, second or first type, having the formula:

[0033]

Embedded image

[Wherein, X and X ′ independently represent hydrogen, a hydroxyl group or an amino group, 1 and m each represent an integer of 0 or 1 or more, and n represents an integer of 1 or more. ]. The alkanolamines preferably used are, for example, N- (2-aminoethyl)
Ethanolamine, diethanolamine, N-methylethanolamine, triethanolamine, N-ethyldiethanolamine, diisopropanolamine, ethanolamine, 4-aminobutanol, N, N-dimethylethanolamine, 3-aminopropanol, N, N-
Ethyl-2,2'-iminodiethanol and the like, or a mixture thereof.

The amines can be used alone or as a mixture with one another. The total concentration of the compound in the neutralized solution is preferably 0.01 mol / l to 0.5 mol / l.
l, more preferably 0.05 mol / l to 0.1 mol / l
include.

The neutralizing solution may contain substances which affect the hydrophobic / hydrophilic balance of the printing plate obtained after processing of the DTR element, for example silica. Further, the neutralizing liquid may include a wetting agent, preferably a compound containing a perfluorinated alkyl group.

The alkaline processing liquid used in developing the imaging element according to the method of the present invention preferably contains a silver halide solvent. The silver halide solvent is preferably 0.01
% By weight, and more preferably from 0.05% to 8% by weight. Silver halide solvents suitable for use in connection with the present invention are, for example, 2-mercaptobenzoic acid, cyclic imides, oxazolidones and thiosulfates. Preferred silver halide solvents to be used in connection with the present invention are thiocyanates and the alkanolamines described above.

According to the invention, the alkanolamines are preferably present in the alkaline processing liquid. However, some or all of the alkanolamine can be present in one or more layers of the imaging element.

Another suitable type of silver halide solvent is a thioether compound. The thioethers preferably used are represented by the following general formula: Z- (R ¹ -S) _t -R ² -SR ³ -Y wherein Z and Y are each independently hydrogen, an alkyl group, an amino group , An ammonium group, a hydroxyl, a sulfo group, a carboxyl, an aminocarbonyl or an aminosulfonyl, wherein R ¹ , R ² and R ³ can each independently be substituted and optionally contain an oxygen bridge And t represents an integer of 0 to 10]. Examples of thioether compounds corresponding to the above formula are, for example, US-P-4.960.683 and EP
-A-554.585.

Still another suitable silver halide solvent is a meso-ionic compound. Preferred meso-ionic compounds for use in connection with the present invention are triazolium thiolates, more preferably 1,2,4-triazolium-3-thiolates.

According to a preferred embodiment of the present invention, at least a portion, and most preferably all, of the meso-ionic compound is present in the alkaline processing liquid used to develop the image-wise exposed imaging element. The amount of the meso-ionic compound in the alkali treatment liquid is preferably 0.1
Mmol / l to 25 mmol / l, more preferably 0.1 mmol / l.
It is from 5 mmol / l to 15 mmol / l, and most preferably from 1 mmol / l to 8 mmol / l.

However, the meso-ionic compound can be inserted into one or more layers contained on the support of the imaging element. In that case meso - ionic compound is preferably 0.1 to 10 mmol / m ^2, more preferably 0.1 to 5 mmol / m ^2, and most preferably 0.5
Contained in the imaging element in a total amount of 1.5 mmol / m ^2. Further details are disclosed in EP-A-0,554,585.

According to the invention, the alkali treatment preferably also comprises a hydrophobizing agent as described above in order to improve the hydrophobicity of the silver image obtained in the image receiving layer. Particularly preferred compounds are 5-
n-heptyl-2-mercapto-1,3,4-oxadiazole and 3-mercapto-4-acetamido-5
n-Heptyl-1,2,4-triazole.

The hydrophobizing agent is preferably present in the alkaline processing liquid at least 0.1 g / l, more preferably at least 0.2 g / l, and most preferably at least 0.3 g / l.
/ L. The maximum amount of hydrophobizing agent will be determined by the type of hydrophobizing agent, the type and amount of silver halide solvent, and the like. Typically the concentration of the hydrophobizing agent is preferably 1.
It is at most 5 g / l, and more preferably at most 1 g / l.

The alkaline processing liquid used according to the present invention is preferably 9 to 14, and more preferably 10 to 1
It has a pH of 3. The pH can be established by an organic or inorganic alkaline substance, or a combination thereof. Suitable inorganic alkaline substances are, for example, hydroxylated,
Carbonic acid, potassium or sodium phosphate, and the like.
Suitable organic alkaline substances are, for example, alkanolamines. In the latter case, the alkanolamines are pH
Or acts as a silver halide complexing agent.

The alkaline processing liquid can also contain the developing agents used according to the invention. In this case, the alkaline processing liquid is called a developer. On the other hand, some or all of the developing agent can be present in one or more layers of the imaging element. When all of the developing agent is included in the imaging element, the alkaline processing liquid is called an activator or activating liquid.

The silver halide developing agents for use according to the invention are preferably of the p-dihydroxybenzene type, for example hydroquinone, methylhydroquinone or chlorohydroquinone, and are 1-phenyl-3-pyrazolidone-type developing agents and / or p-dihydroxybenzenes. Preferably, it is combined with an auxiliary developer which is monomethylaminophenol. Particularly useful auxiliary developing agents are of the phenidone type, for example 1-phenyl-3-pyrazolidone and 1-phenyl-4-monomethyl-3-pyrazolidone. However, other developing agents can be used.

The alkaline processing liquid preferably also contains a preservative having antioxidant activity, for example, sulfite ions provided by, for example, sodium or calcium sulfite. For example, an alkaline aqueous solution is prepared by adding sodium sulfite to a solution of 0.15 to
It is contained in an amount in the range of mol / l. In addition, thickeners such as hydroxyethylcellulose and carboxymethylcellulose, fog inhibitors such as potassium bromide, potassium iodide, and benzotriazoles, which are known to improve print durability, calcium-sequestering compounds, anti-sludge agents, Hardening agents can also be present, including latent hardening agents.

The development is accelerated by using an alkaline processing solution and / or various compounds in one or more layers of the photographic element, preferably, for example, US-P 3,038,805-
4,038,075-4,282,400-4,97
The reaction can be carried out using a polyalkylene derivative having a molecular weight of at least 400 as described in US Pat.

In accordance with the present invention, the imaging element can be exposed in an informed manner in an apparatus according to its particular application, such as a conventional platemaking camera or laser-containing apparatus including a conventional light source.

The imaging element in connection with the present invention for the preparation of a lithographic printing plate comprises a photosensitive layer essentially comprising silver halide,
And an image receiving layer having a water permeable relationship with the emulsion layer on a support.

Layers in water-permeable contact with one another are layers that are continuous with one another or layers that are separated from each other only by a water-permeable layer. The nature of the water-permeable layer is such that it does not substantially inhibit or limit the diffusion of water or compounds contained in the aqueous solution, such as developing agents or complexed silver ions.

Supports suitable for use in accordance with the present invention can be opaque or transparent, for example, a paper support or a resin support. If a paper support is used, it is preferably coated on one or both sides with an alpha-olefin polymer, for example a polyethylene layer, which may optionally contain an antihalation dye or pigment. Organic resin supports, such as cellulose nitrate films, cellulose acetate films, poly (vinyl acetal) films, polystyrene films, poly (ethylene terephthalate) films, polycarbonate films, polyvinyl chloride films or poly-alpha-olefin films, such as polyethylene or polypropylene A film can also be used. The thickness of such an organic resin film is preferably comprised between 0.07 and 0.35 mm. These organic resin supports are preferably coated with a hydrophilic adhesive layer, which can include water-insoluble particles such as silica or titanium dioxide. Metal supports such as aluminum can also be used according to the invention.

The image receiving layer containing physical development nuclei used according to the invention can be free of hydrophilic binders, but preferably comprises a small amount of hydrophilic colloid, such as polyvinyl alcohol, of at most 80% by weight of the total weight of the layer. Including
The hydrophilicity of the surface can be improved. Development nuclei preferably used according to the invention are sulfides of heavy metals, such as antimony, bismuth, cadmium, cobalt,
It is a sulfide of lead, nickel, palladium, platinum, silver and zinc. Particularly suitable development nuclei in connection with the present invention are palladium sulfide nuclei. Other suitable development nuclei are salts such as selenides, polyselenides, polysulfides, mercaptans and tin (II) halides. Heavy metals, preferably silver, gold, platinum, palladium and mercury, can be used in colloidal form.

The silver halide emulsion for use in connection with the present invention consists mainly of silver chloride, but is comprised between 1 mol% and 40 mol%
A proportion of silver bromide can be present. Most preferably, a silver halide emulsion containing at least 70 mol% of silver chloride is used. Emulsions containing more than 5 mol% silver bromide preferably belong to the type of core / shell type well known to those skilled in the art in that substantially all of the bromide is concentrated in the core. . The core preferably contains 10 to 40% of the total silver halide precipitated and the shell preferably contains 60 to 90% of the total silver precipitated.

The photographic silver halide emulsion used in accordance with the present invention is described, for example, in P.I. "Ch" by Glafkids
emie et Physique Photogra
phique ", Paul Montel, Paris
(1967). F. "Photographic Emulsion Ch" by Duffin
emiry ", The Focal Press,
London (1966); L. Ze
“Makingand” by likman et al
Coating Photographic Emu
lsion ", The Focal Press, Lo
As described in Ndon (1966), it can be prepared from soluble silver salts and soluble halides according to various methods.

The average grain size of the silver halide grains is 0.10 to 0.10.
It can be in the range of 0.70 μm, 0.25-0.
45 μm is preferred.

During the precipitation stage, it is preferred to add the iridium and / or rhodium containing compound or a mixture of both. The concentration of these compounds added is 1% of AgNO ₃
10 ^-8 to 10 ^-3 mol, preferably AgNO ₃ , per mol
^{Is in} the range of 0.5 * 10 ^<-7 > to 10 < ^-5 > mol per 1 mol of.

The emulsions can be chemically sensitized during the chemical ripening stage by adding sulfur-containing compounds such as, for example, allyl isothiocyanate, allyl thiourea and sodium thiosulfate. Reducing agent, for example BE-P
Tin compounds as described in 493,464 and 568,687, and derivatives of polyamines such as diethylenetriamine or aminomethanesulfonic acid can also be used as chemical sensitizers. Other suitable chemical sensitizers are noble metals and noble metal compounds such as gold, platinum, palladium, iridium, ruthenium and rhodium. This method of chemical sensitization is described in KOSLOWSKY, Z. Wi
ss. Photogr. Photophys. Photo
ochem. 46, 65-72 (1951).

The silver halide emulsion of the DRE element can be spectrally sensitized according to the spectral emission of the exposure source for which the DTR element is designed.

Suitable sensitizing dyes for the visible spectral region include those described by F.A. M. By Hamer “The Cyanin
e Dyes and Related Compou
nds ", 1964, John Wiley & So
methines as described in ns. Dyes that can be used for this purpose include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, isopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes Is included. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes and complex merocyanine dyes.

In the case of a conventional light source, for example tungsten light, a green sensitizing dye is required. In the case of exposure with an argon ion laser, a blue sensitizing dye is inserted. For exposure with a red light emitting source, such as an LED or HeNe laser, a red sensitizing dye is used. In the case of exposure with a semiconductor laser, a special spectral sensitizing dye suitable for near infrared is required. Suitable infrared sensitizing dyes are, inter alia, US-P 2,0
95,854, 2,095,856, 2,955,93
9,3,482,978,3,552,974,3,5
73,921,3,582,344,3,623,88
1 and 3,695,888.

Preferred blue sensitizing dyes, green sensitizing dyes, red sensitizing dyes and infrared sensitizing dyes in connection with the present invention are EP-A5
54,585.

In order to improve the sensitivity in the red or near infrared region, a so-called supersensitizer can be used in combination with a red or infrared sensitizing dye. A suitable supersensitizer is R
search Disclosure Vol 28
9, May 1988, item 28952. Spectral sensitizers can be added to photographic emulsions in the form of aqueous solutions, solutions or dispersions in organic solvents.

The silver halide emulsions can contain the usual emulsion stabilizers. Suitable emulsion stabilizers are azaindenes,
Preferably tetra- or penta-azaindenes,
Particularly, those substituted with a hydroxy or amino group. Compounds of this type are described by BIRR in Z. Wiss. P
photogr. Photophys. Photoche
m. 47, 2-27 (1952). Other suitable emulsion stabilizers are, inter alia, heterocyclic mercapto compounds such as phenylmercaptotetrazole, quaternary benzothiazole derivatives and benzotriazole.
Preferred compounds are the mercapto-substituted pyrimidine derivatives disclosed in U.S. Pat. No. 3,692,527.

The silver halide emulsion can contain a pH controlling component. Preferably, the emulsion layer is coated at a pH value near the isoelectric point of the gelatin to improve the stability of the coated layer. Other ingredients such as antifoggants, development accelerators, wetting agents and hardeners for gelatin can be present. The silver halide emulsion layers can contain light-screening dyes that absorb scattered light and thus enhance the sharpness of the image. Suitable light-absorbing dyes are, inter alia, US-P 4,092,168, US-P 4,311.
1,787 and DE-P 2,453,217.

Further details regarding the composition, preparation and coating of silver halide emulsions can be found, for example, in Product
Licensing Index, Vol. 92, D
esber 1971, publication
9232, p. 107-109.

In addition to the above-mentioned emulsion layer and image receiving layer, other hydrophilic colloid layers having a water-permeable relationship with these layers can be present. For example, it is particularly advantageous to include a base-layer between the support and the light-sensitive silver halide emulsion layer. In a preferred embodiment of the invention, the base-layer serves as an antihalation layer. Thus this layer can contain the same light absorbing dyes as described above for the emulsion layer;
Finely ground carbon black as described in -P 2,327,828 can be used for the same antihalation purpose. On the other hand, to obtain sensitivity, a light-reflective pigment such as titanium dioxide can be present. In addition, this layer may include hardening agents, matting agents such as silica particles, and wetting agents. At least a portion of these matting agents and / or light-reflective pigments may be present in the silver halide emulsion layer, but it is preferred that the majority be present in the base-layer. In yet another case, the light reflecting pigment can be in a separate layer provided between the antihalation layer and the photosensitive silver halide emulsion layer.

In a preferred embodiment in connection with the present invention, a backing layer is provided on the non-light sensitive side of the support. This layer, which can serve as an anti-curl layer, includes among others matting agents such as silica particles, lubricants, antistatic agents, light absorbing dyes, opacifying agents such as titanium oxide, and hardeners and wetting agents. Can be included.
The backing layer can consist of a single layer or a double layer pack.

The hydrophilic layer usually contains gelatin as a hydrophilic colloid binder. Mixtures of different gelatins with different viscosities can be used to adjust the rheological properties of the layers. Like the emulsion layers, the other hydrophilic layers are preferably coated at a pH value near the isoelectric point of the gelatin. However, instead of or together with gelatin, one or more other natural and / or synthetic hydrophilic colloids, such as albumin, casein, zein, polyvinyl alcohol, arginic acids or their salts, cellulose derivatives, such as Carboxymethyl cellulose, modified gelatin, for example, phthaloyl gelatin and the like can be used.

The hydrophilic layer of the photographic element may be a suitable hardening agent, for example of the vinylsulfone type, for example methylenebis (sulfonylethylene), aldehydes such as formaldehyde, glyoxal and glutar, especially if the binder used is gelatin. Using aldehydes, N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin, active halogen compounds such as 2,4-dichloro-6-hydroxy-s-triazine, and mucohalic acids such as mucohydrochloride and mucophenoxyhydrochloride. Can be hardened. These hardeners can be used alone or in combination. The binders can also be hardened with fast-reactive hardeners, for example carbamoylpyridinium salts of the type described in US Pat. No. 4,063,952.

The hardeners which are preferably used are of the aldehyde type. The hardener can be used in a wide concentration range, but is preferably used in an amount of 4% to 7% of the hydrophilic colloid. Different amounts of hardener can be used in different layers of the imaging element, or the hardening of one layer can be adjusted by diffusion of the hardener from another layer.

The imaging element used in accordance with the present invention may further comprise various types of surfactants in the photographic emulsion layer or at least one other hydrophilic colloid layer. Examples of suitable surfactants are for example EP 545452
It is described in. It is preferable to use a compound containing a perfluorinated alkyl group.

The photographic material of the present invention may further comprise various other additives, such as compounds for improving the dimensional stability of the photographic element,
UV absorbers, spacing agents and plasticizers can be included.

Additives suitable for improving the dimensional stability of the photographic element are, for example, water-soluble or poorly water-soluble synthetic polymers such as alkyl (meth) acrylates, alkoxy (meth) acrylates, glycidyl (meth) Acrylates, (meth) acrylamides,
Polymers of vinyl esters, acrylonitriles, olefins and styrenes, or the above and acrylic acids, methacrylic acids, alpha-beta-unsaturated dicarboxylic acids, hydroxyalkyl (meth) acrylates, sulfoalkyl (meth) acrylates and It is a dispersion of a copolymer with styrene sulfonic acids.

The present invention will now be illustrated by the following examples, which should not be construed as limiting. All parts are by weight unless otherwise specified.

[0077]

【Example】

Preparation of Silver Halide Emulsion Coating Solution A silver chlorobromide emulsion consisting of 98.2 mol% of chloride and 1.8 mol% of bromide was prepared by the double jet precipitation method. Average silver halide grain size is 0.4 μm
(Diameter of a sphere with equal mean volume) and contained rhodium ions as internal dopant. The emulsion was sensitized orthochromatically, and 1-phenyl-5-mercapto-
Stabilized by tetrazole.

A base layer coating solution having the following composition was prepared: gelatin 5.5% carbon black 0.76% silica particles (5 μm) 1.6% Preparation of imaging element 1 Emulsion coating solution and base layer coating solution Was simultaneously coated on a polyethylene terephthalate support provided with a pack of two backing layers using a cascade coating method such that the base layer coating was directly coated on the side of the support opposite the side containing the backing layer . The emulsion layer has a silver halide coverage represented by AgNO ₃ of 1.5 g / m ² ,
Coating was performed so that the gelatin content was 1.5 g / m ² . The emulsion layer further contained 0.15 g / m ² of 1-phenyl-4,4′-dimethyl-3-pyrazolidone and 0.1 g / m ² .
It contained 25 g / m ² of hydroquinone. The base layer was coated such that the amount of gelatin in the coated layer was 3 g / m ² .

The layer of the backing layer pack closest to the support was 0.3 g / m ² of gelatin and 0.5 g / m ² of antistatic agent, co (tetraallyloxyethane / methacrylate / acrylic acid-K-salt). ) Polymer. The second backing layer was 4 g / m ² gelatin, EP 0,08
0.15 g / m ² matting agent consisting of transparent spherical polymer beads having an average diameter of 3 microns according to 0.225;
Hardener of 05g / m ^2, wetting agent triacrylformal and 0.021 g / m ^2, containing the F ₁₅ C ₇ -COONH _4.

The element thus obtained was dried and subjected to a temperature of 40 ° C. for 5 days, then the emulsion layer was charged with 0.7 mg / m ² of PdS as physical development nuclei, 0.4 g / m ² of hydroquinone and 100 mg / M ² of formaldehyde.

Finally, the image forming elements were cut into sheets.

The following treatment solutions were prepared: activator sodium hydroxide 30 g anhydrous sodium sulfite 35 g 2-aminoethyl-aminoethanol 20 ml 1-methyl, 4-allyl, 5-methyl-1,2,4-triazolium-3 -Thiolate 1.1 g 2-mercapto-5-n. Heptyl - oxa - 3,4-diazole 150mg amount neutralized solution to water _{1l A B C D NaH 2 PO} 4 · 2H 2 O 40g 40g 40g 40g non - ionic surfactants 200 mg 200 mg 200 mg 200 mg Table 1 Compound 2 800 mg 800 mg 800 mg 800 mg triethanolamine 10 ml 10 ml 10 ml 10 ml sodium benzoate 1 g 0 g 1 g 1 g sodium sulfite 0 g 4 g 4 g 4 g Turpinal 2NZ ^a) 0 g 0 g 0 g 1 g Water 1 1 1 1 1 1 1 1 1 0 +/- 0.10.

A) Turpinal 2NZ is the trade name of Henkel, Belgium for phosphonic acid, (1-hydroxyethylidene) bis-, disodium salt.

The dampening solution
ion) Water 880 ml Citric acid 6 g Boric acid 8.4 g Anhydrous sodium sulfate 25 g Ethylene glycol 100 g Colloidal silica 28 g Expose the same image forming sheet, develop with the above alkaline activating solution at 20 ° C. for 30 seconds, and then develop The solution was neutralized at 25 ° C. using the neutralizing solution A and dried. Without renewing the processing solution, the camera plate maker DAINI sold by DAINIPPON Ltd, Japan
0.1m / day in PPON SP410
^A printing plate was thus produced in a quantity of ² for 4 weeks.

A printing plate was produced in the same manner by replacing the neutralizing solution A with the neutralizing solutions B, C and D.

The printing plates thus produced on the first day and after 4 weeks were converted to AB, equipped with an Aquamatic dampening system sold by AB Dick Co, USA.
It was mounted on an offset printing press AB DICK 9850 sold by Dick Co, USA and printed under the same conditions. The above dampening solution is dampened with a fountain solution
A 5% concentration was used as the "ain solution". The ink used was ABD 1020 sold by AB Dick Co, USA.

Evaluation: The effect of neutralizer depletion on the number of copies that had to be discarded at the beginning of the printing process due to ink receptivity in the non-printing area, as a function of its composition, is shown in Table 2. Show.

[0088]

[Table 1]

This number corresponds to the newly prepared neutralization solution AD.
Is low when is used. However, after using these neutralizing solutions for 4 weeks, the numbers remain medium or low respectively when neutralizing solutions C and D (solutions of the invention) are used, respectively, while neutralizing solutions B and A respectively. (Comparative solution) results in high and unacceptable high respectively.

The main features and aspects of the present invention are as follows.

1. Imagewise exposing an imaging element comprising a photosensitive layer containing a silver halide emulsion and an image receiving layer containing physical development nuclei on a support; and-exposing the imaging element in the presence of a developing agent and a silver halide solvent. Developing with an alkaline processing solution, the developed image-forming element thus obtained is
It has a pH of 0.5, hydrophobizing agents, buffers and antioxidants active
A method for producing a lithographic printing plate according to a silver salt diffusion transfer method, comprising a step of neutralizing with a neutralizing solution containing a chemical having a property , wherein the neutralizing solution further contains a salt of sulfurous acid.

[0092] 2. The amount of the sulfite salt is 1 g / l to 200 g / l.
The method of claim 1 wherein the amount is in the range of g / l.

3. The hydrophobizing agent has at least 5 carbon atoms.
3. The method according to the above 1 or 2, which is a mercaptotetrazole having a substituent having the following chain.

4. 4. The method according to any one of the above items 1 to 3, wherein the neutralizing solution further contains a blocking compound.

5. 5. The method according to claim 4, wherein the blocking compound is phosphonic acid, (1-hydroxyethylidene) bis- or a disodium salt thereof.

6. The amount of the phosphonic acid, (1-hydroxyethylidene) bis- or disodium salt thereof is 0.10
Item 6. The method according to Item 5, which is contained in an amount of 0 to 10 g / l.

7 . The above-mentioned 1 wherein the neutralized solution further contains an amine.
The method according to any one of claims 6 to 6 .

8 . The amine the following ^formula: Phase in NR ^{1 R} 2 R ³
Hit

Wherein R ¹ is a C ₁ -C ₁₂ containing a hydrophilic group
A hydrocarbon group, R ² and R ³ each independently represent hydrogen, a C ₁ -C ₁₂ hydrocarbon group, or R ² and R 3
³ is completed together with the atoms to which they are attached a 5- or 6-membered ring, provided that the 7 least one of the groups represented by R ² and R ³ are hydrogen or an aliphatic group
The method described in the section.

9 . The amine has the formula:

[0101]

Embedded image

[Wherein, X and X ′ independently represent hydrogen, a hydroxyl group or an amino group, 1 and m each represent 0 or an integer of 1 or more, and n represents an integer of 1 or more. 10. The method according to the above item 9, corresponding to the above.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-278363 (JP, A) JP-A-2-103186 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7 / 07,7 / 00,7 / 40

Claims (1)

(57) [Claims] An image-forming element comprising, on a support, a photosensitive layer containing a silver halide emulsion and an image-receiving layer containing physical development nuclei, image-wise exposed; Developing with an alkaline processing liquid in the presence of a solvent, the developed imaging element thus obtained is
It has a pH of 0.5, hydrophobizing agents, buffers and antioxidants active
Neutralizing with a neutralizing solution containing an agent having a property , wherein the neutralizing solution further contains a salt of sulfurous acid,
A method for producing a lithographic printing plate according to the silver salt diffusion transfer method.